This invention relates to surgical tools, and in particular to a blade saw for scoring and cutting the underside of the mandible at its left and right inferior borders.
In facial surgery a sagittal osteotomy procedure is used to correct either excessive or insufficient protrusion of the lower jaw. With respect to such a procedure there exists a need for a device for scoring and cutting the mandible to facilitate the breaking of the lower jawbone along predetermined lines on both sides of the jaw.
The general idea is to fracture the mandible in the sagittal plane, and then move the now separate central portion of the mandible forward or backward to a more appropriate position, and fix the new jawbone configuration in place so that healing of the fractures can occur. In present methods for accomplishing this type of operation using various types of blades and chisels, there are difficulties in getting the jawbone to split along the desired osteotomy lines.
It would be a great boon to the art of facial surgery if there were a surgical blade saw which could be inserted through an incision in the mouth in an anterior and superior direction so that the blade-containing tip of the saw would be directed inferiorly and posteriorly. The underside of the jawbone could then be scored and cut by back-and-forth motion of the saw blade along a desired line to facilitate breakage of the bone in a controlled manner along a predetermined plane.
Depending on whether the left or right side of the jawbone was being worked on, the blade saw would have to have a right- or left-offset blade-carrying portion to avoid mechanical interference with the jawbone itself. Ideally, such a blade saw would constitute the interchangeable end portion of a motor driven tool providing back-and-forth reciprocating motion along a line. In that case the change from a right-offset blade saw to a left-offset blade saw could be easily made as required during the course of the operation.
The following U.S. Patents are deemed to be of some relevance to the present application.
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 812,507 W. H. Ludewig Feb. 13, 1906 1,455,621 W. H. Joyner Jun. 22, 1921 2,702,550 K. R. Rowe Feb. 22, 1955 2,951,482 G. B. Sullivan Sep. 6, 1960 3,495,329 B. Bothe Feb. 17, 1970 3,554,197 A. K. Dobble Jan. 12, 1971 3,905,105 M. A. Tuke Sep. 16, 1975 3,905,374 R. P. Winter Sep. 16, 1975 4,188,952 V. I. Loschilov et al. Feb. 19, 1980 4,501,484 V. C. Giampapa et al. Mar. 5, 1985 4,615,119 D. S. Johnson et al. Oct. 7, 1986 4,617,930 G. A. B. Saunders Oct. 21, 1986 ______________________________________
The patent to Ludewig is directed to a surgical operating-engine designed to be held in the hand and used as the operative handle for saws, files, chisels, and other instruments used by physicians in operations in nasal passages and other internal cavities of the body. The engine is also adapted for use with dental instruments such as pluggers and cutters. The engine is intended to be connected to a motor to provide reciprocating motion to a surgical tool.
The patent to Sullivan is directed to a surgical saw with a handle shaped to fit the surgeon's hand and a cutting blade which, in one embodiment, is directed at right angles to the hand grip, the shape of the blade having two right-angle bends in it.
The patent to Giampapa et al. is directed to a nasal surgical saw having a concavely curved cutting edge with an angularly offset tip. The shape of the blade is designed to follow the anatomic curve of the nasal-maxillary junction so as to be suitable for use in cosmetic and reconstructive nasal surgery.
The patent to Rowe is directed to a power driven oscillating cutting implement for use in performing surgery in confined spaces. A semicircular saw blade on a long narrow mounting is rapidly oscillated to enable the bony structure of the nose to be cut without damaging the soft membranes.
The patent to Johnson et al. is directed to a vibratory cutter having a plurality of serrated teeth provided on one side of the center line of the cutting blade angled in a first direction, and a plurality of serrated teeth provided on the second side of the center line angled in a second direction, the angles of the teeth provided on either side of the center being equal to one another. The cutting blade is arcuate in nature and the blade vibrates in a back and forth motion in a plane parallel with the object to be severed. The blade cuts in two directions parallel to this surface.